Derivative of
The derivative of is .
f(x) =
Type any function of x; the derivative is computed symbolically in your browser.
How to work it out
- 1
We differentiate with respect to x. The rule that applies is the quotient rule.
- 2
Quotient rule: . Let and .
- 3
Differentiate each piece:
- 4
Put them in the rule:
- 5
Simplify:
- 6
Differentiating once more gives the second derivative, which tells you about curvature:
LaTeX source of the formulas on this page
\[ \frac{d}{dx}\left[\frac{\frac{1}{x}}{x^{4}}\right] = \frac{\frac{-1}{x^{2}} x^{4} - \frac{4 x^{3}}{x}}{\left(x^{4}\right)^{2}} \]
\[ f(x) = \frac{\frac{1}{x}}{x^{4}} \]
\[ u = \frac{1}{x},\quad v = x^{4} \]
\[ u' = \frac{-1}{x^{2}},\quad v' = 4 x^{3} \]
\[ f'(x) = \frac{\left(\frac{-1}{x^{2}}\right)\left(x^{4}\right) - \left(\frac{1}{x}\right)\left(4 x^{3}\right)}{\left(x^{4}\right)^{2}} \]
\[ f'(x) = \frac{\frac{-1}{x^{2}} x^{4} - \frac{4 x^{3}}{x}}{\left(x^{4}\right)^{2}} \]
\[ f''(x) = \frac{\left(\frac{-\left(\left(-2\right) x\right)}{\left(x^{2}\right)^{2}} x^{4} + \frac{-1}{x^{2}} 4 x^{3} - \frac{12 x^{2} x - 4 x^{3}}{x^{2}}\right) \left(x^{4}\right)^{2} - \left(\frac{-1}{x^{2}} x^{4} - \frac{4 x^{3}}{x}\right) 2 x^{4} 4 x^{3}}{\left(\left(x^{4}\right)^{2}\right)^{2}} \]Values of f and f' for 1 / x /
| x | f(x) | f'(x) |
|---|---|---|
| -2 | -0.03125 | -0.078125 |
| -1 | -1 | -5 |
| 0.5 | 32 | -320 |
| 1 | 1 | -5 |
| 2 | 0.03125 | -0.078125 |
| 3 | 0.0041152263 | -0.0068587106 |
Questions
What is the derivative of 1 / x / ?
The derivative of is .
What is the second derivative of 1 / x / ?
((-(-2x) / ()^2 * + -1 / * 4 * - (12 * * x - 4 * ) / ) * ()^2 - (-1 / * - 4 * / x) * 2 * * 4 * ) / (()^2)^2.
Which rule do you use for 1 / x / ?
The quotient rule.
What is the slope of 1 / x / at x = 1?
-5.